//
// Created by denglibin on 2021/3/26.
// 加载图片
#include <SDL.h>
#include <SDL_image.h>
#define WIN_WIDTH 600
#define WIN_HEIGHT 400
#define FRAME_RATE 60 //帧率
static struct SDL_Window * win; //窗口
static struct SDL_Surface * winSurface; //窗口的surface
static struct SDL_Surface * imgSurface; //图片的surface

/**
 * 事件循环
 */
static void eventLoop(){
    SDL_Event  event;
    while (1)
    {//主消息循环
        SDL_PollEvent(&event);
        if(event.type == SDL_QUIT){
            return;
        }
        uint32_t  begin = SDL_GetTicks();
        uint32_t  end = SDL_GetTicks();
        uint32_t  cost = end - begin;
        uint32_t per_frame_time = 1000 / FRAME_RATE;//每一帧耗时ms
        if (per_frame_time > cost){
            //减去循环体耗时，得到还应休眠的时间
             SDL_Delay(per_frame_time - cost);
        }
    }

}


/**
 * 创建显示窗口
 * @return
 */
static int showWindow(){
    //初始化，成功返回0
    if (SDL_Init(SDL_INIT_VIDEO)) {
        SDL_Log("Can not init video %s\n", SDL_GetError());
        return 1;
    }
    win = SDL_CreateWindow("Hello World",
                           SDL_WINDOWPOS_CENTERED,
                           SDL_WINDOWPOS_CENTERED,
                           WIN_WIDTH,
                           WIN_HEIGHT,
                           SDL_WINDOW_SHOWN
    );
    if (win == NULL) {
        SDL_Log("Can not create window %s\n", SDL_GetError());
        return 2;
    }
    winSurface = SDL_GetWindowSurface(win);
    //加载图片返回SDL_Surface
    imgSurface = IMG_Load("img/favorite.png");
    //矩形
    struct SDL_Rect  r = {0, 0, WIN_WIDTH, WIN_HEIGHT};
    //用矩形填充winSurface
    SDL_FillRect(winSurface, &r, 0xFF00AA00);

    //加载图片surface
    SDL_Rect imgR = {0, 0, imgSurface->w, imgSurface->h};
    SDL_BlitSurface(imgSurface, &imgR, winSurface, &imgR);
    SDL_UpdateWindowSurface(win);
    return 0;

}

/**
 * 清理
 */
static void clean(){
    SDL_FreeSurface(imgSurface);
    SDL_FreeSurface(winSurface);
    SDL_DestroyWindow(win);
}
int main2_7(int argc, char* argv[]){
    if (showWindow()){
        exit(1);
    }
    eventLoop();
    clean();
    SDL_Quit();
}

